#include <iostream>
#include <cstring>
using namespace std;

const int N = 100010;
int h[N], e[N], ne[N], idx = 0; //领接表
int color[N];                   //记录各个点颜色的举证
int n, m, a, b;                 //获取输入
int flag = true;                //记录是否发生了冲突

void add(int a, int b)
{
    e[idx] = b;
    ne[idx] = h[a];
    h[a] = idx++;
    return;
}

bool dfs(int u, int c)
{
    color[u] = c;
    for (int i = h[u]; i != -1; i = ne[i])
    {
        int j = e[i];
        if (!color[j])
        {
            if (!dfs(j, 3 - c))
                return false;
        }
        else if (color[j] == c)
            return false;
    }
    return true;
}

int main()
{
    memset(h, -1, sizeof h);
    cin >> n >> m;
    while (m--)
    {
        cin >> a >> b;
        add(a, b);
        add(b, a);
    }
    for (int i = 1; i <= n; ++i)
    {
        if (!color[i])
            if (!dfs(i, 1))
            {
                flag = false;
                break;
            }
    }
    if (flag)
        cout << "Yes";
    else
        cout << "No";
    return 0;
}